1. Field of the Invention
This invention relates to a process of the epoxidation of acid-sensitive aliphatic diene esters.
2. Brief Description of Related Technology
Recently, in the field of microelectronic applications, the need has arisen for an adhesive product to attach a microelectronic component to a circuit board, which in the event of component failure may be exposed to conditions which allow for the removal of the microelectronic component from the circuit board with relative ease. In the past, failure of such components on circuit boards, had been addressed by discarding the circuit board in its entirety--with both faulty component as well as the remaining performing components still on the board. This of course leads to waste, as well as inefficiency.
Accordingly, adhesives have been developed which have been called "reworkable"--that is, the adhesive can be subjected to heat and/or chemical treatment to permit the bond to be broken between the component and the circuit board. This allows the faulty component to be removed from the circuit board, and the new component to be laid down. By so doing, the amount of waste is greatly reduced and production efficiency increased.
Many of the adhesives used for this purpose employ an epoxide based material. See e.g., U.S. Pat. Nos. 5,512,613 and 5,560,934.
Aliphatic diene esters, from which a corresponding epoxide material may be prepared, are sensitive to acid hydrolysis and the reaction of such esters with peracid epoxidizing agents would be expected to be practical only where the reaction mixture has a neutral or basic pH.
Ordinarily, in the synthesis of epoxides from olefins which contain acid sensitive groups, a buffer is added to maintain the reaction mixture at neutral or basic pH during the epoxidation step. However, the use of such buffer, while allowing the reaction to proceed as desired, creates the need to remove the buffer after the reaction has been terminated. The removal step can often be tedious, and adds additional labor and time to the process.
Accordingly, it would be desirable to provide a method of epoxidizing epoxidizable olefinic compounds which does not require use of such a buffer.